In architecture and construction the apparare (from the Latin apparare,[1]​ "prepared", "arranged", also originally opus "Opus (architecture)") in Roman architecture) is the form, structure or constructive arrangement of a wall.

The rigging of a building or wall can be classified according to the material used and the arrangement of the pieces.

The name cutting is given to the theoretical decomposition of a construction into the pieces that form it and can be horizontal, radial, irregular, regular, etc. The square-carved stones are called ashlars and the work made with them is called sillary or stonework.

The regular rig is divided by the size of the ashlars into:.

For the Romans, the measurement was approximately one meter high for the courses of the large rig, half a meter for the courses of the medium rig and ten centimeters for the courses of the small rig.

Depending on the arrangement of the ashlars, the rig receives different names:

If the structure is irregular and made of small stones that are placed by hand, it is called masonry, which is the opus incertum of the Romans and is called filling (the emplecton of the Greeks) when the wall offers a regular exterior facing, with the materials being in bulk or compact concrete inside. Masonry receives different names depending on the materials used in its construction:

In the corner of the wall, the ashlars are arranged vertically so that on one side they are presented lengthwise and on the other, widthwise, which is called major and minor rigging. In brick rigs (opus lateritium of the Romans) and in masonry rigs, vertical courses of ashlar masonry are usually placed for greater strength, forming what are called chains. The one that takes an oblique position and serves as a retaining wall for embankments is called steep wall. The Toledan rig, on the contrary, has horizontal and vertical chains of brick and inserts filled with masonry.

There is a type of masonry called concrete and it is formed with a box in which small stones and mud or cement are placed. If it only contains mud and few stones it is called tapial. This must be supported on stone foundations or plinths and usually has some courses of brick from time to time, called verdugo or verdugada.

The bricks, generally ceramic, have certain measurements and formats and are specifically designed to be joined in a certain way to form a wall, which is why the law of locking or arrangement of bricks in a wall, stipulating from the dimensions of the wall to the meetings and starts "Start (architecture)"), is especially rigid.

Some types of brick masonry are as follows:[1]​.